A database system includes a database and a database management system (DBMS). A database is an organized collection of data. A DBMS comprises computer software that executes on one or more processors and interacts with users, other applications, and a database to capture and analyze data. A DBMS may allow for the definition, creation, querying, update, and administration of databases.
Database systems rely on data replication and synchronization to maintain continuous system availability. Typically, in such a system, a complete copy of the database is stored at a first datacenter and the same complete copy of the database is stored at a second datacenter. The first and second datacenters may be in different locations or they may be in the same location. Since the data in the second datacenter needs to be the same as the data in the first datacenter, a synchronization mechanism is typically employed to handle synchronization of the data. If there is a failure associated with the first datacenter, the system can switch to using the database at the second datacenter without significant issues.
Since the second datacenter may be asked to perform all of the same tasks as the first datacenter, typically, the second datacenter has the same hardware and software requirements as the first datacenter. Sometimes more than two datacenters may be included within a database system.